JPH01133032A - Electrooptic device - Google Patents

Abstract

PURPOSE:To prevent generation of an abnormal display state by providing dummy electrodes to the parts of the spacings between picture element electrodes where line electrodes do not face each other. CONSTITUTION:This electrooptic device is constituted of row electrodes 1, the line electrodes 2, picture element electrodes, nonlinear elements 4, a liquid crystal layer 5, and the dummy electrodes 6. The nonlinear elements 4 are constituted by forming films having nonlinear characteristics in place between the line electrodes 2 and the picture element electrodes 3. Although a strong potential difference is generated in the extremely narrow regions between the row electrodes 1 and the dummy electrodes 6 when the dummy electrodes 6 are provided between the picture element electrodes 3 and 3, the potential of the dummy electrodes 6 is constant in the greater part of the regions and, therefore, the potential gradient by the potential difference of the row electrodes 1 is extremely small and electric fields are as shown by arrows. The parts where the liquid crystal is moved by the presence of the potential difference between the row electrodes and an abnormal display arises are confined to extremely narrow regions. The generation of the abnormal display state is thereby prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electro-optical device using liquid crystal used in large image displays, computer terminals, optical shutters, and the like.

[Summary of the invention]

The present invention prevents the occurrence of abnormal display conditions between pixels by providing a dummy electrode between pixel electrodes of an electro-optical device using a nonlinear element and liquid crystal.

[Conventional technology]

2. Description of the Related Art In recent years, electro-optical devices using liquid crystals, such as those used in display devices or electro-optical soters, have achieved rapid development by taking advantage of their characteristics of being thin, lightweight, and low power consumption. In particular, in matrix-type region crystal electro-optical devices, it has become possible to greatly increase the number of divisions by combining them with nonlinear elements, and the fields of their use have also been greatly expanded.

Nonlinear elements combined with liquid crystals can be classified into 3-terminal devices such as TPT (thin film transistor) and 2-terminal devices such as MIM (metal-insulating film-metal) and MS+ (metal-semi-insulator), but some have simple structures. Therefore, the two-terminal element is advantageous in that the so-called simple matrix type drive circuit without any nonlinear element can be used as is.

A plan view of a conventional electro-optical device using a nonlinear element and a liquid crystal is shown in Fig. 2, and an enlarged plan view thereof is shown in Fig. 3 (al, Fig. 3 [
A plan view of part A of 81 is shown in Figure 3 (bl). In these figures, 1 is a column electrode, 2 is a row electrode, and 3 is a display electrode. An element 4 is formed.However, in FIG. A voltage is applied. When the voltage applied to the nonlinear element 4 via the liquid crystal layer 5 and the pixel electrode 3 exceeds a certain level, charges flow into the pixel electrode 3 through the nonlinear element 4, and the liquid crystal layer 5 in that area turns on. An example of the voltage waveform applied to the column electrodes is shown in Figure 4 (al), and an example of the voltage waveform applied to the row electrodes is shown in Figure 4 (al).
In the waveform example shown in FIG. 4, a checker pattern is displayed.

[Problems to be Solved by the Invention] However, in conventional electro-optical devices using nonlinear elements, the liquid crystal between the column electrode and column Nh is moved due to the potential difference between adjacent columns N and electrodes. This has the disadvantage that a so-called abnormal display state occurs in which the area between the display pixels appears to be displaying.

For example, when displaying a checker pattern, the waveform shown in Figure 4 (+) is applied to the column electrodes as shown in 18.1b (with a half cycle shift for each tree, so the potential difference between adjacent column electrodes is becomes Figure 4 (C1), which causes the liquid crystal molecules to move.As the display pattern determines whether the liquid crystal between the column electrodes moves, there are areas on the entire surface of the device where this phenomenon occurs and areas where it does not. This results in a blurred screen as a whole.This significantly degrades the display quality when displaying images, and causes problems such as incorrect signals being sent when using optical shutters.

The present invention has been made to solve the above problems.

[Means for solving problems]

In the present invention, by providing a dummy electrode between the pixel electrodes, it is possible to prevent the liquid crystal from being moved due to the potential difference between the column electrodes and causing an abnormal display state.

[Effect]

For example, consider how an abnormal display occurs in the diagram shown in FIG. 3('b). It is assumed that the column electrode 1 has a potential difference between the left and right sides. Then, a certain potential gradient is generated in the liquid crystal layer 5 between the column electrodes, and the electric field becomes as shown by the arrow in the figure. (Accurately, it is the potential difference between the left and right between column electrode 1 and pixel electrode 3, but since the left and right pixel electrodes are connected to the same row electrode, there is almost no potential difference. Therefore, it is sufficient to consider only the potential difference between the column electrodes. ) This potential gradient moves the liquid crystal layer and causes an abnormal display state.Here, let's try providing a dummy electrode between the dummy electrodes between the pixel electrodes. Then, a strong potential difference occurs in a very narrow region between the column electrode and the dummy electrode, but since the potential of the dummy electrode is constant in most regions, the potential gradient due to the potential difference of the column electrode becomes extremely small, and the electric field is Therefore, even if there is a potential difference between the column electrodes, the area where the liquid crystal moves and causes an abnormal display is a very narrow area, so there is no problem in practical use.

[Example 1] FIG. 1 [al is an enlarged plan view of the electro-optical device of the present invention, and FIG. 1 [bl is a sectional view taken along the line A-A of fal]. However, for simplicity (column electrodes are omitted in al). In Fig. 1, 1 is a column electrode, 2 is a row electrode, 3 is a pixel electrode, 4 is a nonlinear element, 5 is a liquid crystal layer, and 6 is a dummy electrode. The nonlinear element 4 has a structure in which a film having nonlinear characteristics is sandwiched between the row electrode 2 and the pixel electrode 3.

The dummy electrode 6 was formed by changing the shape of the row electrode 2 and extending it between the pixel electrodes.

An outline of the manufacturing process of this electro-optical device is shown below.

fi+ An ITO film is formed on a glass substrate, and patterned to form a pixel electrode 3 (2) A film having nonlinear characteristics, for example, a film of SiNx, etc., is formed and patterned.

f3) Row electrode 2 is formed by forming a Cr film and patterning it.
and a dummy electrode 6 is formed.

(4) Form an ITO film on the other glass substrate,
Column electrodes 1 are made by patterning.

(5) Two glass substrates are combined so that the column electrode 1 and the row electrode 2 are perpendicular to each other, and the pixel electrode 3 and the column electrode 1 are opposed to each other.

(6) Inject liquid crystal between the substrates.

As mentioned above, the manufacturing process is almost the same as that of conventional electro-optical devices using nonlinear elements. 1st
When the electro-optical device shown in the figure was manufactured and operated, no abnormal display was observed between the display pixels and it exhibited extremely good characteristics.

[Example 2] The same effect can be obtained by using the structure shown in FIG. 5 instead of the electrode structure shown in FIG. 1 (al). In FIG. 5, 2 is a row electrode, 3 is a pixel electrode, and 4 is a nonlinear element. , 6 are dummy electrodes.The difference from Example 1 is that the dummy electrode 6 is not connected to the row electrode, but there is no change in its function as a dummy electrode.In the case of this example, The dummy electrode 6 is made of ITO and is patterned and formed at the same time as the display pixel 3. Therefore, the entire manufacturing process is almost the same as that of a conventional electro-optical device.

〔Effect of the invention〕

As detailed above, according to the present invention, by simply providing a dummy electrode in an electro-optical device using a nonlinear element and a liquid crystal,
The occurrence of an abnormal display state can be prevented without changing the manufacturing process, and an electro-optical device with extremely good characteristics can be realized.

[Brief explanation of the drawing]

FIG. 1 (al is an enlarged plan view of the electro-optical device of the present invention, FIG. 1 Cb) is a cross-sectional view of the A-A' section of fat, FIG. 2 is a plan view of the conventional electro-optical device, and FIG. fal is an enlarged plan view of a conventional electro-optical device, (b) is a sectional view of section B-8' of (al), and FIG. 5 are enlarged plan views of the electro-optical device of the present invention. 1...Column electrode 2...Row electrode 3...Pixel electrode 4...Nonlinear element 5...Liquid crystal layer 6 ...An arrow indicating the direction of the electric field Applicant Seiko Electronics Co., Ltd. Compensation for the electric palm of Honsukero PS Yuhei Cup Whistle 1 Figure (a) Figure 1 (b) Figure 3 (a) 3tE ](a) + B-B''ノ*rjrF+Figure 3 (
b) Figure 4

Claims (2)

[Claims] (1) A liquid crystal layer is provided between a pair of opposing substrates, a plurality of row electrodes are formed on the inner surface of one substrate, and a plurality of pixel electrodes are connected to the row electrodes via a nonlinear element layer. In an electro-optical device in which a column electrode is formed on the inner surface of one of the substrates so as to face the pixel electrode, in a portion of the gap between the pixel electrodes where the column electrode does not face the pixel electrode,
An electro-optical device characterized by being provided with a dummy electrode. (2) The electro-optical device according to claim 1, wherein the dummy electrode is a part of the row electrode extended.